Improvement in artificial legs



rares Arnim* IMPROVEMENT IN ARTIFICIAL LEGS.

Speeilicalion forming part of Leiters Patent No. 7,20L, dated March 19, i850.

a side elevation of the same leg'iiexed at the knee, the body being seated. p Fig. 3 is a rear elevation in a standing posture. Fig. 4. is a horizontal section on the line :c c of Fig. l.

Similar letters in the several figures refer to corresponding parts.

The lower portion of this leg-that is to say, from the ankle to the sole of the foot-includ ing the shank-plate A, curved braces I B, ringplate D, spring-bars E G, adj ustive stops Ej', being described and claimed in my patent for the ankle-supporter,77 granted to me on the 20th day of March, 1849, need not, therefore,

' be particularly described, nor the ballandsocket joint of the knee, nor the ankle-joint.- rlhis skeleton leg is made of thin metallic ribs a, rings or hoops 1),(excepttheknee and socket,) and so combined and united as not to weigh over four or five pounds when completed for an adult, and to be sufficiently strong to bear any required weight. The ribs a run length wise of the leg, and are fastened to the hoops I), which are of the shape of the required leg in its crossssection, and of sizes corresponding to the several portions of the leg for which they are designed. The knee-joint is formed by a horizontal bolt, c, passed through the ball and socket. A spiral spring, d, is attached to the ball of the knee and to a projection or slide, s, placed insidethe leg, near the` ankle, for the purpose of bringing the lower part of the limb forward when in t-he act of stepping.

In order to tighten the spring when it becomes weak, the slide s is made adjust-ive by a mortise and screw.

The adj ustive spring-bars of the ankle may be placed inside the skeleton leg, (instead of the outside, as represented in the drawings) by which arrangement the parts will be out of the way of the boot, which may then be drawn over the parts quite easily.

The socket e, or` pocket to receive the stump of the thigh, is made of leather or other material, and is inserted into and fastened to the upper portion of the metallic skeleton leg, and is provided with suitable straps, h z', by which the leg is secured to the body of the wearer. The strap h is an attachment for buckles to receive the ends of the suspenders after pass ing over the shoulders, and the strap i is for passing around the body and fastening on the side thereof above the hips.

The use of metallic plates might convey the idea that the leg is heavy, but, on the contrary, it is so constructed (as the dr. wings show) of metallic ribs and encircling hoops, so put together that one piece sustains the adjacent piece, rendering it capable of bearing three times the average weight of the human body of an adult and allowing a free circulation of air around the stump, keeping it always cool and healthy, which is a matter of great importance to all who have suffered amputation, rIhe weight of a leg of full length varies from two and a quarter to three and a half pounds, and in very rare cases will it exceed four or five pounds. The motions of the knee and ankle joints approach so near to those of the natural leg as to render it almost impossible to distinguish it from the natural limb when the pantaloons and boots are properly adjusted, and it can be adapted to almost any form of amputation with very little difficulty, even to a stump of three inches projection from the trunk.

The springs in my metallic skeleton leg are so Conveniently arranged and applied as to allow the natural action of the foot, and the leg, instead of hanging back, as is often observed in wooden legs, comes promptly forward and assumes its proper position in obedience to the will of the wearer.

The durable nature of the niaterial and the ingenious manner in which the several parts are arranged and combined render this metalcial leg ever before known or used, and very pleasant and comfortable to the wearer.

lic leg stronger, more lasting, and far moreV symmetrical and elastic than any other artifi- Having thus described the nature, character, andeetion of my artificial leg, what I claim any particular combination with other parts as my invention, and desire to have secured Connected therewith.

to me in this application, is- In testimony whereof I have hereunto signed `skeleton legs of thin metallic ribs vor plates,

The exclusive privilege of making artificial my name before two subscribing witnesses.

GEO. XV. YERGER.

YVitnesses LUND WASHING-TON,

NVM. ELLIOT.

and rings or hoops united together by rivets or other suitable fastenings substantially in the manner herein set forth, irrespective of 

